1. Interdisciplinary Research:Two War Stories
Shashi Shekhar
McKnight Distinguished University Professor
Department of Computer Science and Eng., University of Minnesota 1 1

2. Collaborations With Geographers2
Collaborations With Geographers
All I know about GIS, I learned from Geographers!
And I used that to discover limitations of Computer Science
It helped advance Computer Sc. While helping application domains
University of Minnesota
R. McMaster: co-taught seminar (1994), co-advised students
T. Burk: UMN Map Server ( ) scale up searches
F. Harvey: co-PI on U-Spatial ( ), MN Future Workshop (2009)
S. Ruggles, Minnesota Population Center, NSF Datanet Terrapop
USA
M. Goodchild (UCSB), D. Mark (Buffalo), M. Egenhofer (U Maine)
ESRI: Jack Dangermond, …
UCGIS: Board of Director (2003), Congressional breakfast (2004), …
Intl. Conf. on Geographic Info. Science (2012 Co-chair, 2004 keynote)
American Association of Geographers (AAG) workshops with NIH, …
International
Canada (GEOIDE), Ireland (Geo-computation Center, NUI), India (GIS IIT-Mumbai, UNDP Project), China (Wuhan U, Beijing U), …
Geo-Computation conference (2011, UCL, UK), ISPRS Spatial Data Mining (2006, Turkey), …

3. CCC Visioning Workshop: Making a Case for Spatial Computing 2020 3 3

4. Outline Binary Interdisciplinary Story Ternary Interdisciplinary Story
Computer Science (CS) advancing a Domain Science
Advance both Computer SC. and Domain Science
Ternary Interdisciplinary Story
GIS and CS together address societal needs
Application Domain
Geography
(GIS)
Computer Sc.
Is P = NP ?

5. 5
Story 1 – Clean Water
Source: New York Times (March 11, 2008) (
By 2025,1.8 billion people could be living in water scarce areas
Today, 750 million people live below the water-stress threshold of 1.7 K cubic meters per person
Souce: WFUNA, 15 Global Challenges 5

6. Two Disciplines Civil Engineering Professors Students Computer Science6
Two Disciplines
Civil Engineering
Professors
William Arnold
Ray Holzalski
Miki Hondzo
Paige Novak
Students
Mike Henjum
Christine Wennen
Computer Science
Professors
Shashi Shekhar
Students
Jim Kang
Hydrology
Professors
David Maidment

7. What is Interdisciplinary Research?7
What is Interdisciplinary Research?
Is it multiple Disciplines working on a single project?
Is it one discipline helping another?
My Thoughts:
Ideal: Perform research that enhances all disciplines involved.
Not just a subset!
Very Hard To Do!!!
A lot of asking questions back and forth

8. Challenge: Communication, Finding Win-Win8
Challenge: Communication, Finding Win-Win
Each Discipline has its own language!
We need to learn language of other discipline
Almost like learning a foreign language
Ex.: meaing of “infrastructure” and “network”
Disciplines have different values, cultures and goals
Mis-understanding of what each discipline really is
e.g., “I thought Civil Engineering was all about building bridges!”
e.g., “I thought Computer Science was all about programming!”
Break down barriers
Keep talking to each other and have an open mind when discussing each others interest

9. Brainstorming: In the Beginning…9
Brainstorming: In the Beginning…
Computer Science Questions
Do you plan on having more than 5 sensors? Like 1000 or 10,000 or more?
CE Ans:
No Way!
The cost of each sensor ranges from 10 to 100k
Civil Engineering Questions
How is Computer Science involved in this work?
CS Ans:
I don’t know!
Need to understand the domain questions and the dataset first 9

10. Brainstorming: A little later…10
Brainstorming: A little later…
Civil Eng. Questions
Can you remove errors from the dataset?
CS Ans:
Yes,
But, not really CS work
Existing techniques already exist
e.g., Triggers
Computer Science Questions
Do you want to know how fast the river is flowing?
CE Ans:
Not really,
We can already determine that by the discharge, water depth, and physical characteristics of the river 10

11. Brainstorming: Light at the end of the tunnel11
Brainstorming: Light at the end of the tunnel
Computer Science Questions
Are you interested in finding point sources in both space and time?
CE Ans:
Yes!
Its too hard to find this manually
e.g., hours to sift through the data
50k data points per measured variable
Civil Engineering Questions
Can you find when and where interesting contaminants may enter the river?
CS Ans:
Yes!
Flow Anomaly 11

12. 12
Win-Win Question What time periods have unexpected events between sensors?
Sensor 5
Sensor 1
Sensor 2
Sensor 3
Sensor 4
(Source:
(Source: Shingle Creek, MN Study Site)
Ex. An Oil Spill
Contributions:
Computer Science: New algorithm for problems where dynamic programming fails
Environmental Science: Localize pollution sources 12

13. Outline Binary Interdisciplinary Story Ternary Interdisciplinary Story
Computer Science (CS) advancing a Domain Science
Advance both Computer SC. and Domain Science
Ternary Interdisciplinary Story
GIS and CS together address societal needs
Problem Formulation Constraints
Deliver value to application domain
Computational Feasibility
(Geographic) Data Feasibility
Application Domain
Geography
(GIS)
Computer Sc.
Is P = NP ?

14. Large Scale Evacuation
( National Weather Services)
( FEMA.gov)
I-45 out of Houston
Houston
(Rita, 2005)
Florida, Lousiana (Andrew, 1992) (
( National Weather Services)
Hurricane: Andrews, Rita
Traffic congestions on all highways
E.g. 100-mile congestion (TX)
Great confusions and chaos
"We packed up Morgan City residents to evacuate in the a.m. on the day that Andrew hit coastal Louisiana, but in early afternoon the majority came back home. The traffic was so bad that they couldn't get through Lafayette."
Mayor Tim Mott, Morgan City, Louisiana ( )

15. Problem Statement Given Output Objective Constraints
A transportation network, a directed graph G = ( N, E ) with
Capacity constraint for each edge and node
Travel time for each edge
Number of evacuees and their initial locations
Evacuation destinations
Output
Evacuation plan = a set of origin-destination routes & schedule
Objective
Minimize evacuation time
Constraints
(Spatio-temporal) Data Feasibility
Computational Scalability to large population and geographies

16. Spatio-temporal Data Feasibility
Digital Road Maps
Are Navteq, OpenStreetMap digital roadmaps adequate?
Capacity constraints: TP+ (Tranplan) has major roads
Evacuee Population
Is Census Data adequate? Timely?
Day-time – employment, school, tourist, events, …
Location-aware Smart-phones ?estimate real-time population

17. Computational Feasibility
A. Transportation Science: Dynamic Traffic Assignment
- Game Theory: Wardrop Equilibrium, e.g. DYNASMART (FHWA), DYNAMIT(MIT)
Limitation: Nice Game Theory,but Extremely high computation time
- Does not scale to medium size networks and populations!
B. Operations Research: Time-Expanded Graph + Linear Programming
- Optimal solution, e.g. EVACNET (U. FL), Hoppe and Tardos (Cornell U).
Limitation: - High computational complexity => Does not scale to large problems
- Users need to guess an upper bound on evacuation time
Inaccurate guess => either no solution or increased computation cost!
> 5 days
108 min
2.5 min
0.1 min
EVACNET Running Time
50,000
5,000
500 50
Number of Nodes
C. Computer Science: Capacity Constrained Route Planner
- Extends shortest-path algorithms to honor capacity constraints
- Scales up to to Millions of evacuees over hundreds of square miles

18. Win-Win Contributions: Ex. An Oil Spill18
Win-Win
Contributions:
Computer Science: New algorithm to scale up to metropolitan scenarios
Transportation Science: Walking first mile speeds up evacuation by factor of 3
Ex. An Oil Spill 18

19. Dimensions Beyond Data & Computing
(Spatio-temporal) Data Availability
Estimating evacuee population, available transport capacity
Pedestrian data: walkway maps, link capacities based on width
Traffic Eng.
Link capacity depends on traffic density
Modeling traffic control signals, ramp meters, contra-flow, …
Evacuee Behavior (Social Science)
Unit of evacuation: Individual or Household
Heterogeneity: by physical ability, age, vehicle ownership, language, …
Policy Decisions
How to gain public’s trust in plans? Will they comply?
When to evacuate? Which routes? Modes? Shelters? Phased evacuation?
Common good with awareness of winners and losers due to a decision
Science
How does one evaluate an evacuation planning system ?

20. Lessons Learned Interdisciplinary Research is HARD22
Lessons Learned
Interdisciplinary Research is HARD
Hardest part is trying to understand the other domain
Crucial that both sides understand each other before research can begin
A lot of trial and error between both sides
Once an “Ah-ha” moment occurs
The number of opportunities can be unlimited!